// Copyright 2018 The ksonnet authors
//
//
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.

package params

import (
	"github.com/ksonnet/ksonnet/pkg/util/jsonnet"
	"github.com/pkg/errors"
)

// BuildEnvParamsForModule builds environment parameters for a specific module.
//
// Given the following paramsStr and moduleName `app.project-1`, return
// only the parameters with that prefix.
// ```
// {
// 	components: {
// 	  "app.project-1.deployment": {
// 		replicas: 1,
// 	  },
// 	  "infra.security.deployment": {
// 		name: "tool",
// 	  },
// 	  "deployment": {
// 		replicas: 3,
// 	  },
// 	},
//   }
// ```
func BuildEnvParamsForModule(moduleName, paramsStr, componentParams, envDir string) (string, error) {
	script, err := loadScript("params_for_module.libsonnet")
	if err != nil {
		return "", errors.Wrap(err, "loading script")
	}

	vm := jsonnet.NewVM()
	vm.TLAVar("moduleName", moduleName)
	vm.TLACode("input", paramsStr)
	vm.ExtCode("__ksonnet/params", componentParams)
	vm.AddJPath(envDir)

	output, err := vm.EvaluateSnippet("params-for-module", script)
	if err != nil {
		return "", errors.Wrap(err, "evaluating params for module")
	}

	return output, nil
}
